How do I put my gate into the animation editor?

I've read the ROBLOX wiki on animations, and I've added an AnimationController to the model like it said. I then tried to animate the gate with the animation editor, but only one part goes onto the editor. Is there a way so I can get my whole model into the editor at the same time, so I can make an opening/closing animation?

You cannot animate anything other than humanoids in the animation editor. You can add things like Torque, other constraints, or even just manually set it's rotation, but you can't really use animation editor on anything other than people.

the only way you could do that is to use the model creator plugin, that would allow you to make joints, and then animate it that way